KR0120195B1 - Method for manufacturing polyphenylene sulphide - Google Patents

Abstract

Synthetic method of polyphenylene sulfide is provided in this invention. In the reaction of dihalo aromatic compound and alkali metal sulfide in organic solvent to yield polyphenylene sulfide, when the reaction is performed about 50-90%, and prepolymer of polyphenylene sulfide is yet to be precipitated, 1 to 20 mole % of metallic carbonyl compound represented by formula Mn(CO)m for dihalo aromatic compound is added, then reaction is completed. Metallic carbonyl compound is selected from Fe(CO)5, Ni(CO)4, Co2(CO)5, Mn2(CO)10, Re2(CO)10, W(CO)6 etc.

Description

Method for producing polyphenylene sulfide

The present invention relates to a method for producing polyphenylene sulfide, and more particularly, to a method for producing high molecular weight polyphenylene sulfide having intrinsic viscosity and high polymerization degree of 0.2 or more.

Polyphenylene sulfide, also called PPS, is a synthetic resin of polysulfides, and has excellent mechanical properties, dimensional stability, and chemical resistance, so it can replace engineering metals such as engineering plastics, chemical instruments, pipe valves, and pump blades. Widely used.

Such polyphenylene sulfides can be represented by compounds of the general formula (I):

N represents an integer of 1 or more.

Various methods of manufacturing PPS as described above are known in the art.

US Patent No. 3,919,177 discloses a process for preparing high molecular weight polyphenylene sulfides by adding RCOOM in the polymerization of p-dichlorobenzene and Na ₂ S in an N-methyl-2-pyrrolidone solvent. (Wherein R is a hydrocarbonyl group and M is Na or K).

However, the polyphenylene sulfide obtained by this method has a problem that not only the molecular weight is low but also the intrinsic viscosity reaches only 0.16 to 0.23.

Japanese Patent Application Laid-Open No. 55-43139 discloses p-dihalobenzene and alkali metal sulfides (except lithium sulfide) in N-methyl-2-pyrrolidone solvent represented by the following general formulas A, B and C. A process for producing high viscosity poly-p-phenylene sulfides is disclosed by reacting in the presence of at least one compound selected from the group consisting of aromatic sulfonic acid alkali salts:

(Wherein R is an alkyl group having 1 to 12 carbon atoms, n is 0, 1 or 2, and M is an alkali metal such as sodium, potassium, rubidium or cesium)

However, poly-p-phenylene sulfide obtained by such a method has a problem that the molecular weight is low and the melt viscosity reaches about 4,000 poise.

In addition, Japanese Patent Application Laid-Open No. 61-7332 discloses a method of reacting an alkali metal sulfide with a dihaloaromatic compound in an N-methyl-2-pyrrolidone solvent to obtain a polyarylene sulfide,

A) 0.5 to 2.4 moles of water per mole of alkali metal sulfide are carried out at a temperature of 180 to 235 ° C. to give polyarylene sulfide having a melt viscosity of 5 to 300 poises to dihaloaromatic compounds. A process for producing at a conversion ratio of 50 to 98 mol%,

(B) Melt viscosity by adding water so that 2.5 to 7.0 moles of water per mole of alkali metal sulfide is present and increasing the temperature to 245 to 290 ° C to continue the reaction. A method for producing a polyarylene sulfide having a valence of 1000 or more is disclosed.

However, the polyarylene sulfide obtained by the above-described method not only has a low molecular weight, but the reaction is composed of two stages, so that the process is complicated, and furthermore, the operation risk increases due to the reaction being performed under high pressure. have.

The present invention has been made to solve the problems of the prior art as described above, the object of the present invention is to provide a method for producing a polymer polyphenylene sulfide having an intrinsic viscosity and high polymerization degree of 0.2 or more, in a simpler process It is.

In order to achieve the object as described above, the present invention, in the production of polyphenylene sulfide by polymerizing a dihaloaromatic compound and an alkali metal sulfide in an organic amide solvent, the reaction is carried out at 180 ° C to 240 ° C After the reaction proceeds by 50 to 90% under temperature conditions, a high molecular weight polyphenylene is added, in which the metal carbonyl compound is added in an amount of 1 to 20 mol% and the reaction is terminated before the prepolymer is precipitated. Provided is a method for preparing sulfide.

That is, the present invention will be described in more detail, in order to prepare a high molecular weight polyphenylene sulfide by reacting a dihaloaromatic compound and an alkali metal compound,

1) The alkali metal sulfide of the following general formula (III) is first reacted with the dihaloaromatic compound of the following general formula (II) in an organic amide solvent at a temperature of 180 to 240 ° C (the reaction rate at this time is 50 to About 90%, which is a step before the resulting polymer of formula IV is precipitated),

2) Before the start of the second stage reaction, the metal carbonyl compound of the following general formula (V) is added in an amount of 1 to 20 mol% or less with respect to 1 mol of the dihaloaromatic compound (II), and the following general formula (VI) To form an arene-transition metal complex,

3) Next, the arene-transition metal complex (VI) and the prepolymer (IV) are reacted in an organic amide solvent at a temperature of 240 to 300 ° C. to complete the secondary polymerization. Provided is a process for preparing polyphenylene sulfide of:

Wherein X is a halogen atom, M 'is an alkali metal, preferably Na or K, M is a transition metal, preferably Cr, Mo, W, Fe, Ni, Mn or Re, 1, n , p is an integer of 1 or more, m is an integer of 4,5,6,8 or 10.

In particular, in the present invention, as the metal carbonyl compound [M (CO)], Fe (CO), Ni (CO) ₄ , Co ₂ (Co) ₈ , Mn ₂ (CO) ₁₀ , Re ₂ (CO) ₁₀ , It provides a method for producing polyphenylene sulfide, characterized in that using W (CO) ₆ , Cr (CO) ₆ , MO (CO) ₆ and the like.

Examples of dihalobenzenes usable in the present invention include p-dichlorobenzene, p-dibromobenzene, p-diiodobenzene, 1-chloro-4-bromobenzene, 1-phenyl-2-chloro-5-bro A mother benzene etc. are mentioned, Preferably, p-dichlorobenzene is mentioned.

Examples of the organic amide solvent that can be used in the method of the present invention include, for example, N-methylformamide, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, tetramethyl Urea, and N-methyl-2-pyrrolidone is preferable.

As mentioned above, the metal carbonyl compound represented by the following general formula (V) is a generic term for a complex having a carbonyl group (CO) as a ligand and includes V, Cr, Mn, Fe, Co, Ni, Mo, W, Ru, Many transition metals are known, such as Rh, Ir, Re:

[M _n (CO) _m ] (Ⅴ)

Wherein n is 1 or 2 and m represents 4,5,6,8 or 10.

As already pointed out above, the prior art method simply does not polymerize p-dichlorobenzene and Na ₂ S in N-methyl-2-pyrrolidone (NMP) to obtain a high degree of polyphenylene sulfide. It was.

Therefore, in the present invention, the cyclic compound having π electrons reacts with various kinds of metal carbonyl compounds to easily form an arene-transition metal complex (π-complex), thereby resulting in a highly reactive π-complex. Based on the knowledge of the present invention that the heavy ring (ring) moiety can be used as a substrate in a new aromatic substitution reaction, the desired high polymerization degree polyphenylene sulfide can be obtained by carrying out the reaction of the present invention in two steps. That is, as can be seen in the above reaction scheme, in the first stage reaction of the present invention, the reaction products are preferably reacted with p-dichlorobenzene and Na ₂ S in a conventional manner until their reaction rate reaches 50 to 90%. Let's do it. This first stage reaction is a stage prior to precipitation of the prepolymer produced as described above. Before entering the second stage reaction according to the present invention, in the present invention, the metal carbonyl compound [M _n (CO) _m ] is added in an amount of 1 to 20 mol% based on 1 mol of p-dichlorobenzene before the prepolymer is precipitated. By adding below to form p-dichlorobenzene and arene-transition metal complex to increase the reactivity of p-dichlorobenzene, the second stage reaction proceeds to obtain high molecular weight polyphenylene sulfide having intrinsic viscosity of 0.2 or more Can be.

That is, in the present invention, after reacting p-dichlorobenzene and Na ₂ S in an organic amide solvent at a reaction rate of 50 to 90% or less under a temperature condition of 180 to 240 ℃, before the prepolymer precipitates, The carbonyl compound [Mn (CO) m] is added at 1-20 mol% or less with respect to 1 mol of p-dichlorobenzene, and it reacts at the temperature of 240-300 degreeC, It is characterized by completing superposition | polymerization.

Meanwhile, examples of the metal carbonyl compound usable in the present invention include Fe (CO) ₅ , Ni (CO) ₄ , W (CO) ₆ , MO (CO) ₆ , Cr (CO) ₆ , Mn ₂ (CO) _10, and the like Re ₂ (CO) _10, their amount used is a 1 to 20% by mole are preferable. When the amount of the metal carbonyl compound is less than 1 mol%, the effect of forming the transition metal complex is so weak that it is difficult to obtain a desired high polymerization polyphenylene sulfide, and when the amount is more than 20 mol% Finally, after the desired polymer is obtained, it is difficult to remove the metal carbonyl compound remaining in the reaction liquid even after the post-treatment is performed to remove impurities, and the crystallinity of the obtained polymer compound is lowered, and PPS is desired. There arises a problem of not having physical properties as the same engineering plastic product.

As pointed out above, the intrinsic viscosity of the final product obtained by the present invention is represented by 0.2 or more.

Intrinsic viscosity is according to H. Kramer,

Is defined as:

In the above formula, c represents a concentration expressed as g / 100cm ³ (solution), ηsp is a specific viscosity, and ηr is a relative viscosity.

The slope of this straight line in the above equation is a function of [η], and at low concentrations it can be expressed as

In addition, in the branched chain polymer, [η] is a continuous function of the chain length, and according to H. Steaudinger,

Where M is the molecular weight and k is one constant for a given homologous compound.

Therefore, the molecular weight of a polymer can be estimated roughly by examining these relationship which makes a polymer intrinsic viscosity into one parameter.

In the method according to the present invention, in the arene-transition metal complex (π-complex) produced during the reaction, the electron density of the benzene ring portion is reduced, so that the nucleophilic substitution reaction occurs easily, and thus the rate of polymerization is increased. Since the bulky -M (CO) _P substituent is attached to the polymer chain formed in the middle of the reaction, the solubility of the polymer is increased, and the reaction can be carried out with high polymerization before the prepolymer is precipitated.

Therefore, the present invention can easily obtain a high molecular weight polyphenylene sulfide having an intrinsic viscosity of 0.2 or more by performing the secondary reaction in the presence of a metal carbonyl compound.

EXAMPLE

Next, preferred examples and comparative examples of the present invention are described. However, these examples are only for illustrating the present invention in more detail, and the present invention is not limited only to these examples.

Example 1

120.1 g (0.50 mol) of sodium sulfide hexahydrate and 200 ml of N-methyl-2-pyrrolidone were introduced into a 500 ml high-pressure reactor equipped with a stirrer, and then gradually to 205 캜 over 2 hours. Nitrogen gas was passed while raising the temperature to remove 48 ml of water. After cooling the high-pressure reactor at 170 ° C., 94.2 g (0.50 mol) of p-dichlorobenzene solution dissolved in 30 ml of N-methyl-2-pyrrolidone was introduced into the high-pressure reactor described above, and a nitrogen gas atmosphere. After the high pressure reactor was closed under the above, the temperature of the reactor was gradually raised to 210 ° C. over about 30 minutes, and then the contents of the reactor were stirred for about 3 hours. After cooling the autoclave to a temperature of 170 ° C., 11.0 g (0.05 mole) of Cr (CO) ₆ solution dissolved in 20 ml of N-methyl-2-pyrrolidone was added to the above autoclave and subjected to 3 atm. After the high pressure reactor was sealed under a nitrogen gas atmosphere, the temperature of the reactor was gradually raised to about 250 ° C. over 1 hour and 30 minutes, and then the contents of the reactor were stirred for about 4 hours.

After the completion of the polymerization, the reactor was cooled, the resulting product was filtered, washed five times with 300 ml of 5% aqueous hydrochloric acid solution, washed five times with 300 ml of water, and then in a vacuum dryer at 80 ° C. After drying for 5 hours, about 482 g (yield: 87.4%) of a compound were obtained. The intrinsic viscosity of the product obtained in this example was 0.40.

The inherent viscosity of the product obtained by the method as described above was measured at a temperature of 206 ° C. in 1-chloronaphthalene, with a concentration of the polymer polymer dried at 0.4 g / 100 cm ³ .

EXAMPLES 2-9

Instead of 120.1 g (0.50 mol) used in Example 1 described above, 124.9 g (0.52 mol) of sodium sulfide hexahydrate was used, and various metals corresponding to 0.005 to 0.003 mol instead of Cr (CO) _{6 were} used. The carbonyl compound was used to perform a series of reactions under the reaction conditions as shown in Table 1 below to obtain a series of results as shown in Table 1 below.

[Examples 10-15]

Instead of the various kinds of metal carbonyl compounds used in Examples 2 to 9 described above, chromium carbonyl (Cr (CO)) was used to carry out the reaction under various reaction conditions as shown in Table 2 below. A series of results were obtained as shown in.

[Comparative Example]

124.9 g (0.52 mole) of sodium sulfide hexahydrate, 200 ml of N-methyl-2-pyrrolidone and 68.0 g (0.5 mole) of sodium acetate, trihydrate in a high-pressure reactor equipped with a stirrer After the addition, the mixture was heated up and passed through nitrogen while maintaining a temperature of 200 ° C. over 2.25 hours to remove 32.5 ml of water. The high pressure reactor was cooled to a temperature of 175 ° C, 94.2 g (0.50 mole) of p-dichlorobenzene solution dissolved in 25 ml of N-methyl-2-pyrrolidone was added, and the high pressure reactor was reacted under a nitrogen gas atmosphere of 1.5 atm. After closing, the autoclave was gradually warmed over 0.5 hours and stirred for 3 hours. Again, the high-pressure reactor was cooled to room temperature, the obtained polymer was filtered, washed 7 times with 500 ml of water, dried for 3 hours under a vacuum dryer at 80 ° C., and the resulting 47.8 g (yield: 88.0%) of the polymer material was obtained.

The inherent viscosity of the polymer obtained in this Comparative Example was found to be 0.24.

As can be seen in detail through various examples and comparative examples as described above, according to the preferred embodiments of the present invention a high polymerization degree of polyphenylene sulfide having a high yield of at least 88% and an intrinsic viscosity of at least 0.2 Although the intrinsic viscosity of the product obtained by the comparative example belonging to the prior art which does not add a metal carbonyl compound is 0.24, it turns out that intrinsic viscosity is remarkably low.

Claims (3)

In a method for producing a polyphenylene sulfide by reacting a dihaloaromatic compound and an alkali metal sulfide in an organic amide solvent, the compound is reacted by 50 to 90% to obtain a prepolymer of the obtained polyphenylene sulfide. A method for producing a polyphenylene sulfide, characterized in that the reaction is completed by adding a metal carbonyl compound [M _n (CO) _m ] to the reaction solution before the precipitation. The method for producing polyphenylene sulfide according to claim 1, wherein the metal carbonyl compound is added in an amount of 1 to 20 mol% with respect to the dihaloaromatic compound. The method of claim 1 or claim 2, wherein the metal carbonyl _{compounds, Fe (CO) 5, Ni} (O) 4, Co 2 (CO) 8, Mn 2 (CO) 10, Re 2 (CO) 10 , W (CO) | ₆ , Cr (CO) ₆ , Mo (CO) ₆ The compound production method of any one of polyphenylene sulfide characterized by the above-mentioned.